09-04-2025
A global study reveals the hidden impact of human activities on plant biodiversity
A study published in the journal Nature and coordinated by researchers from the University of Tartu has highlighted the significant, but often invisible, impact of human activities on plant biodiversity. More than 200 scientists collaborated on the DarkDivNet project, launched in 2018, including researchers José M. Blanco-Moreno and Aaron Pérez-Haase from the Biodiversity Research Institute of the University of Barcelona.
This project studied plant communities at 5,500 sites in 119 regions around the world to identify dark diversity, that is, native species that could inhabit a given location but are not present. At each site, local researchers recorded all plant species. The probability of species co-occurrence allowed them to assess the full potential of plant diversity at each site and measure how much of the potential diversity was actually present. The difference between the set of potential species and what was observed is hidden diversity. This way of assessing biodiversity revealed the hidden impact of human activities on natural vegetation.
The results indicate that in regions with low human impact, ecosystems contain more than one-third of potentially suitable species. In contrast, in regions heavily affected by human activities, ecosystems contain only one in five suitable species. Traditional measures of biodiversity, such as observed species richness, often fail to detect this impact because natural variation in biodiversity across regions and ecosystems can hide the true extent of human impact.
The level of human disturbance in each region was measured using the Human Footprint Index, which includes factors such as human population density, land-use changes (such as urban development and agriculture), and infrastructure (roads and railways). The study found that a location's plant diversity is negatively influenced by human influences, both nearby and hundreds of kilometers away. According to Professor Pärtel, lead author of the study: "This result is alarming because it shows that human disturbance has a much broader impact than previously thought, even reaching nature reserves. Pollution, logging, littering, trampling, and human-caused fires can exclude plants from their habitats and prevent their recolonization”.
The methods used to measure dark diversity offer valuable tools for ecological restoration, helping to identify missing species and devise strategies for their reintroduction. Furthermore, this approach highlights the need for greater ecosystem protection beyond nature reserves, in support of the global goal of protecting 30% of the Earth's land surface.
This project studied plant communities at 5,500 sites in 119 regions around the world to identify dark diversity, that is, native species that could inhabit a given location but are not present. At each site, local researchers recorded all plant species. The probability of species co-occurrence allowed them to assess the full potential of plant diversity at each site and measure how much of the potential diversity was actually present. The difference between the set of potential species and what was observed is hidden diversity. This way of assessing biodiversity revealed the hidden impact of human activities on natural vegetation.
The results indicate that in regions with low human impact, ecosystems contain more than one-third of potentially suitable species. In contrast, in regions heavily affected by human activities, ecosystems contain only one in five suitable species. Traditional measures of biodiversity, such as observed species richness, often fail to detect this impact because natural variation in biodiversity across regions and ecosystems can hide the true extent of human impact.
The level of human disturbance in each region was measured using the Human Footprint Index, which includes factors such as human population density, land-use changes (such as urban development and agriculture), and infrastructure (roads and railways). The study found that a location's plant diversity is negatively influenced by human influences, both nearby and hundreds of kilometers away. According to Professor Pärtel, lead author of the study: "This result is alarming because it shows that human disturbance has a much broader impact than previously thought, even reaching nature reserves. Pollution, logging, littering, trampling, and human-caused fires can exclude plants from their habitats and prevent their recolonization”.
The methods used to measure dark diversity offer valuable tools for ecological restoration, helping to identify missing species and devise strategies for their reintroduction. Furthermore, this approach highlights the need for greater ecosystem protection beyond nature reserves, in support of the global goal of protecting 30% of the Earth's land surface.